Downloaded songs play on Macbook but not on iPhone

[dontickmyyum]

Songs that I've downloaded from outside of Spotify play on my computer (Macbook Air running MacOS Sierra 10.12.4) don't play on my iPhone (iPhone SE running iOS 10.2.1). They're on playlists that have been downloaded to the iPhone and to the Macbook Air. Also, there are other songs that are from within Spotify that also have the same problem. For example: Broken Jaw by Foster the People from the album Torches. It is on Spotify, plays in my Spotify on the Macbook, is downloaded to the iPhone, but has the green arrow and also the blacked-out lettering and won't play.

Thanks for your help!

[dontickmyyum]

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